(a) Field of the Invention
The present invention relates to a clutch system that selectively transmits torque in an automatic transmission. More particularly, the present invention relates to a clutch system having enhanced operability and durability.
(b) Description of the Related Art
Generally, at least one clutch is disposed in an automatic transmission, and each clutch is selectively operated at respective speeds in order to change a gear ratio.
That is, when an input torque is applied to at least one input element of the automatic transmission, the input torque is selectively transmitted to another operation element by operation of the clutch. In this process, rotation speed of the input speed is changed to a targeted rotation speed, and the targeted rotation speed is outputted through an output element.
Operation of an automatic transmission is well-known to a person of ordinary skill in the art, and thus a detailed description thereof will be omitted.
The clutch receives torque from the rotation axis, and the torque is sequentially transmitted to clutch disks, plates, and a retainer in the clutch.
Clutch disks and plates can be moved along an axial direction of the rotation axis, and are selectively contacted with each other by operation of a piston.
In addition, automatic transmission fluid flows in the clutch in order to cool the clutch, and is exhausted between the disks and the plates.
However, since a conventional clutch has waves only along a circumferential direction thereof, cooling performance of the clutch disk deteriorates when the clutch rotates.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.